Trichomoniasis

Maybe you haven't heard of this infection before. It is the stepchild of sexually transmitted disease—one that is hard enough to pronounce, let alone find information about why it is important to avoid.
Ironically, trichomoniasis (trick-o-mon-i-a-sis or "trich") is the most common non-viral sexually transmitted disease (STD) in the U.S. In recent years, however, diagnosing and treating this disease has become a greater priority as new research has shown that it is not quite as harmless as was once thought.
Each year, an estimated five million cases of trichomoniasis occur in the U.S. Left untreated, in most cases it usually causes no symptoms. But it can cause vaginitis in some women and non-gonococcal urethritis in men. Both women and men infected with trichomoniasis appear to be more at risk of acquiring HIV (human immunodeficiency virus) and other STDs.
If trichomoniasis is so common and causes significant risks to women's health, one would expect to find more interest in its prevention. There are several reasons that this STD has been ignored. First, its symptoms—primarily discharge and irritation of the vagina and urethra—have been seen as troubling but not taken as serious as other STDs. And second, the most common treatment, a drug called metronidazole, is highly effective and has not been threatened by the development of resistant organisms that have caused problems in treating other STDs.
The organisms that causes trichomoniasis are protozoan (the simplest, single-cell organism in the animal kingdom) called trichomonads, the most common being Trichomonas vaginalis. This parasite resides primarily in the genitourinary tract, where it finds the warmth and moisture needed to grow and multiply.
Trichomoniasis is the least common of three types of vaginitis. The other two are bacterial vaginosis (BV), which is an overgrowth of normal bacteria found in the vagina, and vulvovaginal candidiasis, more commonly known as yeast infection. Trichomoniasis makes up only about five percent of vaginal infections.
As with BV, recent research has clearly shown that trichomoniasis can be associated with pre-term delivery complications. In 1997, for example, a study of U.S. women found that the STD was associated with a 40 percent increase in pre-term low birth weight. While other studies have shown a similar link between trichomoniasis and adverse delivery events, the research is not conclusive about how much treatment can reduce pregnancy complications.
Research also links trichomoniasis with an increased risk of HIV transmission (HIV is the virus that leads to AIDS). Although more study is needed, experts estimate that women infected with this STD are at two to four times higher at risk of acquiring HIV than uninfected women. The reason for this increased risk is that vaginitis increases a response from the immune system, producing more of the cells that HIV targets for infection.
Trichomoniasis is transmitted primarily through sexual intercourse. It is most common in persons who are at their peak of sexual activity. Infection with other STDs and having multiple sex partners are primary factors that put women at higher risk. Rarely, trichomoniasis may be transmitted by a pregnant woman to her baby during childbirth.
In the U.S., about five percent to 10 percent of women are infected. Among women infected with other STDs, such as gonorrhea, the rate of trichomoniasis is much higher, exceeding 50 percent in some studies. For reasons not entirely clear, African American women have higher rates (more than double in some studies) than Caucasians and Hispanic and Latina women.